The dynamic-from-file:// syntax is supported for metadata database URLs but not for data source database URLs

[Kashish3009]

Issue description

The dynamic-from-file:// syntax is supported for metadata database URLs but not for data source database URLs in Hasura's current implementation.

Observed per doc: https://hasura.io/docs/2.0/security/dynamic-secrets/#configuration-for-metadata-database

Describe the solution you'd like

Allow users to set DATABASE_URL from_env' variables in metadata/databases.yaml file with the ability to be set to dynamic-from-file for data source database urls, like the graphql metadata env url.

Workaround

When a sed command (a stream editor tool in Unix/Linux) to edit the databases.yaml file during deployment.

This command replaces instances of from_env with dynamic-from-file specifically for staging.